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From Sudheer Vinukonda <>
Subject Re: Query about Server Session pool Sharing
Date Wed, 11 Jan 2017 01:04:35 GMT
It depends on if the first 10 transactions are parallel/concurrent or they occur in some order.
In short, as long as there's an idle connection in the pool, it will be reused. New origin
connections are made only when there's currently no idle connection that can be leveraged.

Origin max connections setting is typically only used when there's a known limitation on the
Origin to support beyond certain fixed number of connections, otherwise, it's best to not
configure it and let ATS automatically reuse/make new connections depending on the rate of
incoming requests.



> On Jan 10, 2017, at 4:43 PM, Vamsi Ambati <> wrote:
> Followup question, by setting  
> ‘proxy.config.http.server_session_sharing.pool’ to global 
> proxy.config.http.origin_max_connections to say 10
> My understanding of the above configuration is, for first 10 new http transactions destined
to the origin server( results in establishing  10 new SSL sessions  with the origin
> So for the first 10 http transactions , one has to experience the SSL negotiation over
head and for the 11th Http transaction destined to, then ATS uses one among the existing
10 ssl sessions in the pool. 
> Then RTT for the 11th Http transaction will be lower than first 10 Http transactions.
> Is my understanding correct ?
> -Vamsi
>> On Jan 10, 2017, at 3:19 PM, Bryan Call <> wrote:
>> There is no affinity on the transaction based on the origin server.  The client connection
is assigned to a thread using round robin.
>> The connection pools will grow as large as they need to fulfill the incoming requests.
 There is generally more connections to the origin when using thread pools.  There is a way
to set a maximum number of connections to the origin using server_max_connections and origin_max_connections.

>> We are working on using session tickets to the origin to reduce the amount of overhead
in creating a new TLS connections.
>> Docs:
>> -Bryan
>>> On Jan 5, 2017, at 11:44 AM, Vamsi Ambati <> wrote:
>>> We are using  ATS 7.0  and trying to understand the server session pool sharing
>>> We have found a configuration attribute  proxy.config.http.server_session_sharing.pool
which takes values as ‘global’/‘thread’.
>>> My understanding for the value of ‘thread’ is that each thread  maintains
the server session pool and not shared by other threads.
>>> My question is , Do ATS  for any two Http transactions whose origin server is
same say like affines to the same thread ?
>>> If so, how big is the pool ? How many  max  sessions will be accumulated  in
the pool ?Would these values changes for ‘thread’ and ‘global’ ?
>>> My question is from the perspective of reusing the SSL server sessions as  much
as possible .
>>> Regards
>>> Vamsi

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